A head-mounted display such as a helmet-mounted display or eyeglass-mounted display (abbreviated herein as a “HMD”) is a display device worn on the head of an individual that has one or more small display devices located near one eye or, more commonly, both eyes of the user.
Some HMDs display only simulated (computer-generated) images, as opposed to real-world images, and accordingly are often referred to as “virtual reality” or immersive HMDs. Other HMDs superimpose (combine) a simulated image upon a non-simulated, real-world image. The combination of non-simulated and simulated images allows the HMD user to view the world through, for example, a visor or eyepiece on which additional data relevant to the task to be performed is superimposed onto the forward field of view (FOV) of the user. This superposition is sometimes referred to as “augmented reality” or “mixed reality.”
Combining a non-simulated, real-world view with a simulated image can be achieved using a partially-reflective/partially-transmissive optical surface (a “beam splitter”) where the surface's reflectivity is used to display the simulated image as a virtual image (in the optical sense) and the surface's transmissivity is used to allow the user to view the real world directly (referred to as an “optical see-through system”). Alternatively, a direct view display having transmissive properties, e.g., a transparent organic light-emitting diode display (TOLED), can be used to combine a non-simulated, real-world view with a simulated image. Combining a real-world view with a simulated image can also be done electronically by accepting video of a real world view from a camera and mixing it electronically with a simulated image using a combiner (referred to as a “video see-through system”). The combined image can then be presented to the user as a virtual image (in the optical sense) by means of a reflective optical surface, which in this case need not have transmissive properties, or using a direct view display, which likewise need not have transmissive properties.
From the foregoing, it can be seen that HMDs can provide the user with: (i) a combination of a simulated image and a non-simulated, real world image, (ii) a combination of a simulated image and a video image of the real world, or (iii) purely simulated images.
Sighting devices have long been used to help shooters improve the placement of shots fired from small-arms weapons. Small-arms weapons include those firearms that an individual may carry and use. Many handguns, for instance, include unmagnified iron sighting devices with horizontal and vertical reference points that allow a shooter to align the gun parallel to the shooter's line of sight. Other firearms, such as carbines, rifles, assault rifles and light machine guns, may include magnified sighting devices (which are also known as telescopic sights, or scopes) to provide a shooter with improved accuracy in aligning the barrel with the intended target. These magnified sighting devices are especially useful for hunters, sharpshooters, and others who find it advantageous to shoot at targets from a great distance. Successfully hitting any target depends on a shooter's ability to understand a bullet's likely flight path, or trajectory, referred to as ballistics, before the bullet is fired.
Further sighting devices have recently included the use of cameras mounted on weapons that provide a video input corresponding to where the weapon is aimed to a head mounted display. These types of devices allow a person to aim a gun around an obstacle without having to place their heads in a potential line of fire. The devices, however, do not provide endpoint information for the ammunition to be fired by the weapon and, in particular, do not provide endpoint information within the user's forward field of view.
The present disclosure addresses this existing need in the art by providing methods and apparatus that permit a user to operate a weapon while continuing to observe his/her forward field of view with a predicted endpoint for the weapon's ammunition upon firing being readily visible within the user's forward field of view (viewing area) even as the orientations of the weapon and/or the viewing area change over time.